A high power cavity harmonic filter

Abstract

The invention provides a high-power cavity harmonic filter, belonging to the technical field of harmonic filters. The high-power cavity harmonic filter comprises a first coaxial feed tube outer conductor, one end of the first coaxial feed tube outer conductor is fixedly connected to an aluminum alloy cavity, the inner wall of the first coaxial feed tube outer conductor is fixedly connected to a first polytetrafluoroethylene disk, the inner wall of the first polytetrafluoroethylene disk is fixedly connected to a first metal connecting rod, the high-power cavity harmonic filter, the harmonic filter has distributed capacitors and inductors inside, three supporting structures are designed to fix the capacitors and inductors, one end of the supporting structure is connected to a flat plate capacitor at one end up and down, and the size of the capacitor can be changed by moving the supporting structure, so that the operating frequency and matching condition of the harmonic filter can be adjusted, thereby ensuring that the adjusted harmonic filter can completely suppress high-order harmonics and operate reliably and stably under high suppression.

Description

Technical Field

[0001] The invention belongs to the technical field of harmonic filters, and in particular relates to a high-power cavity harmonic filter. Background Art

[0002] High-power harmonic filters are very important components in RF transmission systems. When harmonic suppression is not high enough, higher harmonics will be emitted through the antenna, causing interference to other devices. Since the practical frequencies of broadcast communication transmitters are generally 5MHz, 10MHz, 15MHz, 20MHz, etc., the corresponding higher harmonics are second harmonics, third harmonics, fourth harmonics, fifth harmonics, sixth harmonics, etc., and higher harmonics generally do not cause interference due to their low energy. Working at an operating frequency of 25MHz, the highest cutoff higher harmonic that can be transmitted is 150MHz. Therefore, the designed harmonic filter must meet the high suppression of frequencies within 150MHz.

[0003] In the field of broadcasting and communication, high-power, easy-to-install, stable and reliable filters are needed to filter out high-order harmonics to prevent interference with aircraft wireless communications, radar communications, etc. Harmonic filters are an important part of the radio frequency system and are important equipment installed between the transmitting source and the terminal antenna. They filter out high-order harmonic signals other than the fundamental wave. Whether the harmonic filter can work stably and reliably directly affects the transmission effect and fault duration of the transmitter. The suppression of high-order harmonics is the prerequisite for allowing the transmitter to start working. Therefore, existing harmonic filters have the problems of incomplete suppression of high-order harmonics, difficult installation of high-power harmonic filters, and high manufacturing costs. Summary of the invention

[0004] The object of the present invention is to provide a high-power cavity harmonic filter, aiming to solve the problem of incomplete suppression and instability of high-order harmonics of harmonic filters transmitting signals in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A high-power cavity harmonic filter comprises a first coaxial feed tube outer conductor, one end of the first coaxial feed tube outer conductor is fixedly connected to an aluminum alloy cavity, the inner wall of the first coaxial feed tube outer conductor is fixedly connected to a first polytetrafluoroethylene disk, the inner wall of the first polytetrafluoroethylene disk is fixedly connected to a first metal connecting rod, the outer surface of the first metal connecting rod is fixedly connected to a first metal vertical plate, the upper surface of the first metal vertical plate is fixedly connected to a first metal horizontal plate, the lower surface of the first metal vertical plate is fixedly connected to a second metal horizontal plate, the lower surface of the first metal horizontal plate is fixedly connected to a first spiral inductor, one end of the first spiral inductor is fixedly connected to a metal plate, the other side of the metal plate is fixedly connected to a second spiral inductor, one end of the second spiral inductor is fixedly connected to a second metal vertical plate, the upper surface of the metal plate is fixedly connected to a metal top plate, and the lower surface of the metal plate is fixedly connected to a metal bottom plate.

[0006] In order to enable the high-power cavity harmonic filter to achieve the effect of signal input, as a preferred embodiment of the present invention, a first coaxial feed inner conductor is fixedly connected to one side of the first polytetrafluoroethylene disk.

[0007] In order to enable this high-power cavity harmonic filter to achieve the signal output effect, as a preferred embodiment of the present invention, a second coaxial feed tube outer conductor is fixedly connected to one side of the aluminum alloy cavity, a second polytetrafluoroethylene disk is fixedly connected to the inner wall of the second coaxial feed tube outer conductor, and a second coaxial feed tube inner conductor is fixedly connected to one side of the second polytetrafluoroethylene disk.

[0008] In order to enable this high-power cavity harmonic filter to achieve the effect of fixing the second metal vertical plate, as a preferred embodiment of the present invention, the inner wall of the second polytetrafluoroethylene disk is fixedly connected with a second metal connecting rod, and one end of the second metal connecting rod is fixedly connected with the second metal vertical plate.

[0009] In order to enable this high-power cavity harmonic filter to achieve the effect of cooling air entering the interior of the device, as a preferred embodiment of the present invention, an upper air inlet hole is opened at the top of one side of the aluminum alloy cavity close to the outer conductor of the first coaxial feed tube, and a lower air inlet hole is opened at the bottom of one side of the aluminum alloy cavity close to the outer conductor of the first coaxial feed tube.

[0010] In order to enable the high-power cavity harmonic filter to achieve the effect of cooling the first spiral inductor by cooling air, as a preferred embodiment of the present invention, a first upper cooling air hole is opened on one side of the first metal vertical plate, and a first lower cooling air hole is opened on the other side of the first metal vertical plate.

[0011] In order to enable the high-power cavity harmonic filter to achieve the effect of cooling the second spiral inductor by cooling air, as a preferred embodiment of the present invention, an upper inner cooling air hole is opened and closed at the top of one side of the metal plate, and an lower inner cooling air hole is opened at the bottom of one side of the metal plate.

[0012] In order to enable the high-power cavity harmonic filter to achieve the effect of cooling the metal top plate and the metal bottom plate by cooling air, as a preferred embodiment of the present invention, a first top cooling air hole is opened on the upper surface of the metal top plate, a second top cooling air hole is opened on the lower surface of the metal top plate, a first bottom cooling air hole is opened on the upper surface of the metal bottom plate, and a second bottom cooling air hole is opened on the lower surface of the metal bottom plate.

[0013] In order to enable the high-power cavity harmonic filter to achieve the effect of cooling air flowing out of the space between the metal plate and the second metal vertical plate, as a preferred embodiment of the present invention, a second upper cooling air hole is opened on one side of the second metal vertical plate, and a second lower cooling air hole is opened on the other side of the second metal vertical plate.

[0014] In order to make this high-power cavity harmonic filter achieve the effect of a cooling air outflow device, as a preferred embodiment of the present invention, an upper air outlet hole is opened on the top of one side of the aluminum alloy cavity close to the outer conductor of the second coaxial feed tube, and a lower air outlet hole is opened on the bottom of one side of the aluminum alloy cavity close to the outer conductor of the second coaxial feed tube.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The high-power cavity harmonic filter is provided with an aluminum alloy cavity, a first spiral inductor, a second spiral inductor, a first metal vertical plate, a first metal horizontal plate, a second metal horizontal plate, a metal top plate, a metal bottom plate, a second metal vertical plate and a metal plate. The inside of the harmonic filter is a distributed capacitor and inductor, which can be equivalent to a parallel LC loop in circuit form. The capacitor is a flat plate capacitor, and a capacitor will be formed between the flat plates of the aluminum alloy structure. The inductor is a spiral structure and is installed vertically, thereby ensuring the convenience of installation and maintenance and keeping it fixed during long-distance transportation. Three supporting structures are designed to fix the capacitor and inductor, and the supporting structure at one end is connected to the flat plate capacitor at one end up and down. The size of the capacitor can be changed by moving the supporting structure, and the operating frequency and matching of the harmonic filter can be adjusted, thereby ensuring that the adjusted harmonic filter can completely suppress high-order harmonics and operate reliably and stably under high suppression.

[0017] 2. The high-power cavity harmonic filter is provided with a first coaxial feed tube outer conductor, a first coaxial feed tube inner conductor, a second coaxial feed tube outer conductor, a second coaxial feed tube inner conductor and an aluminum alloy cavity. The first coaxial feed tube outer conductor and the first coaxial feed tube inner conductor are used as signal input and output ports, and the second coaxial feed tube outer conductor and the second coaxial feed tube inner conductor are used as signal output ports. The characteristic impedance of the signal input and output ports and the signal output port is 75 ohms. Since coaxial feed lines are used for transmission of short-wave communication frequencies, a high power of 100 kW can be output by adopting the form of internal and external feed tubes. Since the shape of the aluminum alloy cavity is rectangular, it is not only conducive to processing, but also convenient to form capacitors with various metal plates inside.

[0018] 3. The high-power cavity harmonic filter is provided with a first metal horizontal plate, a second metal horizontal plate, a metal top plate, a metal bottom plate, a second metal vertical plate, a metal plate, a first spiral inductor and a second spiral inductor. Since the capacitors inside the filter are composed of various metal plates, they can replace ceramic capacitors, which reduces costs, reduces the types of materials and the difficulty of installation. At the same time, the spiral design of the first spiral inductor and the second spiral inductor can increase the inductance, and can also facilitate the adjustment of the inductance. When the output frequency changes, it can be adjusted by reducing the number of inductor turns or changing the turn spacing.

[0019] 4. The high-power cavity harmonic filter, through the arrangement of the upper air inlet, the lower air inlet, the upper air outlet, the lower air outlet, the inner upper cooling air hole, the inner lower cooling air hole, the first top cooling air hole, the second top cooling air hole, the first bottom cooling air hole, the second bottom cooling air hole, the first upper cooling air hole, the first lower cooling air hole, the second upper cooling air hole and the second lower cooling air hole, the cooling air enters from the upper air inlet and the lower air inlet, cools the first spiral inductor after passing through the first upper cooling air hole and the first lower cooling air hole, and then cools the second spiral inductor through the inner upper cooling air hole and the inner lower cooling air hole. In addition, a part of the cooling air passes through the first top cooling air hole, the second top cooling air hole, the first bottom cooling air hole and the second bottom cooling air hole to cool the metal top plate and the metal bottom plate, and finally the cooling air passes through the second upper cooling air hole and the second lower cooling air hole and leaves the filter from the upper air outlet and the lower air outlet, thereby facilitating the cooling of the inside of the filter and ensuring the stable use of the harmonic filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2It is a schematic diagram of the axonometric structure of the first polytetrafluoroethylene disk in the present invention;

[0023] Figure 3 Schematic diagram of the isometric structure of the first spiral inductor and the second spiral inductor in the present invention;

[0024] Figure 4 It is a schematic diagram of the isometric structure of the first metal connecting rod and the second metal connecting rod in the present invention;

[0025] Figure 5 is a schematic diagram of the axonometric structure of the first metal vertical plate in the present invention;

[0026] Figure 6 It is a schematic diagram of the axonometric structure of the metal top plate in the present invention.

[0027] In the figure: 1, first coaxial feed tube outer conductor; 2, first coaxial feed tube inner conductor; 3, second coaxial feed tube outer conductor; 4, second coaxial feed tube inner conductor; 5, aluminum alloy cavity; 6, upper air inlet; 7, lower air inlet; 8, upper air outlet; 9, lower air outlet; 10, first spiral inductor; 11, second spiral inductor; 12, first polytetrafluoroethylene disk; 13, second polytetrafluoroethylene disk; 14, first metal connecting rod; 15, second metal connecting rod; 16, first metal vertical plate ; 17. First metal horizontal plate; 18. Second metal horizontal plate; 19. Metal top plate; 20. Metal bottom plate; 21. Second metal vertical plate; 22. Metal plate; 23. Inner upper cooling air holes; 24. Inner lower cooling air holes; 25. First top cooling air holes; 26. Second top cooling air holes; 27. First bottom cooling air holes; 28. Second bottom cooling air holes; 29. ​​First upper cooling air holes; 30. First lower cooling air holes; 31. Second upper cooling air holes; 32. Second lower cooling air holes. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example

[0030] See also Figure 1-6The present invention provides the following technical solution: a high-power cavity harmonic filter, comprising a first coaxial feed tube outer conductor 1, one end of the first coaxial feed tube outer conductor 1 is fixedly connected to an aluminum alloy cavity 5, the inner wall of the first coaxial feed tube outer conductor 1 is fixedly connected to a first polytetrafluoroethylene disk 12, the inner wall of the first polytetrafluoroethylene disk 12 is fixedly connected to a first metal connecting rod 14, the outer surface of the first metal connecting rod 14 is fixedly connected to a first metal vertical plate 16, the upper surface of the first metal vertical plate 16 is fixedly connected to a first metal The lower surface of the first metal horizontal plate 17 and the first metal vertical plate 16 are fixedly connected to the second metal horizontal plate 18, the lower surface of the first metal horizontal plate 17 is fixedly connected to the first spiral inductor 10, one end of the first spiral inductor 10 is fixedly connected to the metal plate 22, the other side of the metal plate 22 is fixedly connected to the second spiral inductor 11, one end of the second spiral inductor 11 is fixedly connected to the second metal vertical plate 21, the upper surface of the metal plate 22 is fixedly connected to the metal top plate 19, and the lower surface of the metal plate 22 is fixedly connected to the metal bottom plate 20.

[0031] In a specific embodiment of the present invention, through the arrangement of the aluminum alloy cavity 5, the first spiral inductor 10, the second spiral inductor 11, the first metal vertical plate 16, the first metal horizontal plate 17, the second metal horizontal plate 18, the metal top plate 19, the metal bottom plate 20, the second metal vertical plate 21 and the metal plate 22, the interior of the harmonic filter is a distributed capacitor and inductor, which can be equivalent to a parallel LC loop in circuit form. The capacitor is a flat plate capacitor, and a capacitor will be formed between the flat plates of the aluminum alloy structure. The inductor is a spiral structure and is installed vertically, thereby ensuring the convenience of installation and maintenance and keeping it fixed during long-distance transportation. In order to fix the capacitor and inductor, three supporting structures are designed. The three supporting structures are all plates made of metal. The first supporting structure is the first metal vertical plate 16, which functions as the first metal horizontal plate 17 and the second metal horizontal plate 18, so that the first metal horizontal plate 17 and the second metal horizontal plate 18 form a capacitor with the metal top plate 19 and the metal bottom plate 20. In addition, during testing, the first metal supporting structure The vertical plate 16 can move left and right on the first metal connecting rod 14, and can be welded together once the adjustment is completed. The second supporting structure is a metal plate 22, and its function is to support the metal top plate 19 and the metal bottom plate 20, so that a capacitor is formed between the metal top plate 19 and the metal bottom plate 20 and the first metal horizontal plate 17 and the second metal horizontal plate 18 and the aluminum alloy cavity 5. In addition, the metal plate 22 also plays a role in supporting the first spiral inductor 10 and the second spiral inductor 11. The third supporting structure is a second metal vertical plate 21, and its main function is to support the second spiral inductor 11. The second metal vertical plate 21 can also move left and right on the second metal connecting rod 15 during testing, and can be welded together once the adjustment is completed. Therefore, the supporting structure at one end is connected to a flat plate capacitor at one end up and down. Moving the supporting structure can change the size of the capacitor, and thus adjust the operating frequency and matching of the harmonic filter, thereby ensuring that the adjusted harmonic filter can completely suppress high-order harmonics and operate reliably and stably under high suppression conditions.

[0032] Specifically, one side of the first polytetrafluoroethylene disk 12 is fixedly connected to the first coaxial feed tube inner conductor 2 .

[0033] In this embodiment, by providing the first coaxial feed tube outer conductor 1 and the first coaxial feed tube inner conductor 2 , both of them serve as a signal input port, which facilitates the signal input of the device.

[0034] Specifically, the second coaxial feed outer conductor 3 is fixedly connected to one side of the aluminum alloy cavity 5 , the second coaxial feed outer conductor 3 is fixedly connected to the inner wall of the second coaxial feed outer conductor 3 , and the second coaxial feed inner conductor 4 is fixedly connected to one side of the second polytetrafluoroethylene disk 13 .

[0035] In this embodiment, by providing the second coaxial feed tube outer conductor 3 and the second coaxial feed tube inner conductor 4, both of them serve as a signal output port, which facilitates the signal output of the device.

[0036] Specifically, a second metal connecting rod 15 is fixedly connected to the inner wall of the second polytetrafluoroethylene disk 13 , and one end of the second metal connecting rod 15 is fixedly connected to the second metal vertical plate 21 .

[0037] In this embodiment, the second metal vertical plate 21 is fixed by the second metal connecting rod 15 .

[0038] Specifically, an upper air inlet hole 6 is opened at the top of the aluminum alloy cavity 5 close to the first coaxial feed tube outer conductor 1 , and a lower air inlet hole 7 is opened at the bottom of the aluminum alloy cavity 5 close to the first coaxial feed tube outer conductor 1 .

[0039] In this embodiment, the upper air inlet hole 6 and the lower air inlet hole 7 are provided to facilitate cooling air to enter the interior of the device.

[0040] Specifically, a first upper cooling air hole 29 is opened on one side of the first metal vertical plate 16 , and a first lower cooling air hole 30 is opened on the other side of the first metal vertical plate 16 .

[0041] In this embodiment, the first upper cooling air hole 29 and the first lower cooling air hole 30 are provided to facilitate cooling of the first spiral inductor 10 by cooling air.

[0042] Specifically, an inner upper cooling air hole 23 is opened and closed at the top of one side of the metal plate 22 , and an inner lower cooling air hole 24 is opened and closed at the bottom of one side of the metal plate 22 .

[0043] In this embodiment, the upper inner cooling air holes 23 and the lower inner cooling air holes 24 are provided to facilitate cooling of the second spiral inductor 11 by cooling air.

[0044] Specifically, a first top cooling air hole 25 is opened on the upper surface of the metal top plate 19, a second top cooling air hole 26 is opened on the lower surface of the metal top plate 19, a first bottom cooling air hole 27 is opened on the upper surface of the metal bottom plate 20, and a second bottom cooling air hole 28 is opened on the lower surface of the metal bottom plate 20.

[0045] In this embodiment, the first top cooling air hole 25 , the second top cooling air hole 26 , the first bottom cooling air hole 27 and the second bottom cooling air hole 28 are provided to facilitate cooling of the metal top plate 19 and the metal bottom plate 20 by cooling air.

[0046] Specifically, a second upper cooling air hole 31 is opened on one side of the second metal vertical plate 21 , and a second lower cooling air hole 32 is opened on the other side of the second metal vertical plate 21 .

[0047] In this embodiment, the second upper cooling air hole 31 and the second lower cooling air hole 32 are provided to facilitate cooling air to flow out of the space between the metal plate 22 and the second metal vertical plate 21 .

[0048] Specifically, an upper air outlet 8 is formed at the top of the aluminum alloy cavity 5 close to the second coaxial feed tube outer conductor 3 , and a lower air outlet 9 is formed at the bottom of the aluminum alloy cavity 5 close to the second coaxial feed tube outer conductor 3 .

[0049] In this embodiment, the upper air outlet 8 and the lower air outlet 9 are provided to facilitate the cooling air to flow out of the device.

[0050] The electrical components mentioned in this article are all connected to an external main controller and 220V mains electricity, and the main controller can be a conventional known device for controlling a computer or the like.

[0051] The working principle and use process of the present invention: When the high-power cavity harmonic filter is in use, three supporting structures are designed inside it to fix the capacitor and inductor. The three supporting structures are all made of metal plates. The first supporting structure is a first metal vertical plate 16, which functions as a first metal horizontal plate 17 and a second metal horizontal plate 18, so that the first metal horizontal plate 17 and the second metal horizontal plate 18 form a capacitor with a metal top plate 19 and a metal bottom plate 20. In addition, during testing, the first metal vertical plate 16 of the supporting structure can move left and right on the first metal connecting rod 14, and can be welded together once the adjustment is completed. The second supporting structure is a metal plate 22, which functions to support the metal top plate 19 and the metal bottom plate 20. The bottom plate 20 forms a capacitor between the metal top plate 19 and the metal bottom plate 20 and the first metal horizontal plate 17 and the second metal horizontal plate 18 and the aluminum alloy cavity 5. In addition, the metal plate 22 also supports the first spiral inductor 10 and the second spiral inductor 11. The third supporting structure is the second metal vertical plate 21, which mainly supports the second spiral inductor 11. The second metal vertical plate 21 can also be moved left and right on the second metal connecting rod 15 during testing. Once the adjustment is completed, they can be welded together. Therefore, the support structure at one end is connected to the flat plate capacitor at one end up and down. Moving the support structure can change the size of the capacitor, and thus the operating frequency and matching of the harmonic filter can be adjusted.

[0052] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-power cavity harmonic filter, comprising a first coaxial feed outer conductor (1), characterized in that: One end of the first coaxial feed tube outer conductor (1) is fixedly connected to an aluminum alloy cavity (5); the inner wall of the first coaxial feed tube outer conductor (1) is fixedly connected to a first polytetrafluoroethylene disk (12); one side of the first polytetrafluoroethylene disk (12) is fixedly connected to a first coaxial feed tube inner conductor (2); one side of the aluminum alloy cavity (5) is fixedly connected to a second coaxial feed tube outer conductor (3); the inner wall of the first polytetrafluoroethylene disk (12) is fixedly connected to a first metal connecting rod (14); the outer surface of the first metal connecting rod (14) is fixedly connected to a first metal vertical plate (16); the upper surface of the first metal vertical plate (16) is fixedly connected to a first metal connecting rod (14); A first metal horizontal plate (17) is fixedly connected to the surface; a second metal horizontal plate (18) is fixedly connected to the lower surface of the first metal vertical plate (16); a first spiral inductor (10) is fixedly connected to the lower surface of the first metal horizontal plate (17); one end of the first spiral inductor (10) is fixedly connected to a metal plate (22); the other side of the metal plate (22) is fixedly connected to a second spiral inductor (11); one end of the second spiral inductor (11) is fixedly connected to a second metal vertical plate (21); the upper surface of the metal plate (22) is fixedly connected to a metal top plate (19); and the lower surface is fixedly connected to a metal bottom plate (20).

2. A high-power cavity harmonic filter according to claim 1, characterized in that: A second polytetrafluoroethylene disk (13) is fixedly connected to the inner wall of the second coaxial feed tube outer conductor (3), and a second coaxial feed tube inner conductor (4) is fixedly connected to one side of the second polytetrafluoroethylene disk (13).

3. A high-power cavity harmonic filter according to claim 2, characterized in that: A second metal connecting rod (15) is fixedly connected to the inner wall of the second polytetrafluoroethylene disk (13), and one end of the second metal connecting rod (15) is fixedly connected to a second metal vertical plate (21).

4. A high-power cavity harmonic filter according to claim 1, characterized in that: An upper air inlet hole (6) is provided at the top of one side of the aluminum alloy cavity (5) close to the first coaxial feed tube outer conductor (1), and a lower air inlet hole (7) is provided at the bottom of one side of the aluminum alloy cavity (5) close to the first coaxial feed tube outer conductor (1).

5. The high-power cavity harmonic filter according to claim 1, characterized in that: The first metal vertical plate (16), the metal plate (22), the metal top plate (19), and the second metal vertical plate (21) are all provided with cooling air holes.

6. A high-power cavity harmonic filter according to claim 1, characterized in that: An upper air outlet hole (8) is provided at the top of one side of the aluminum alloy cavity (5) close to the second coaxial feed tube outer conductor (3), and a lower air outlet hole (9) is provided at the bottom of one side of the aluminum alloy cavity (5) close to the second coaxial feed tube outer conductor (3).

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